Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of getting a good idea when it's possible to plant catharanthus is to check out the USDA zone info for Savoy.

Planting Calendar for Catharanthus

Frost tolerance for catharanthus:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably not a good idea to plant catharanthus until after the last frost because they require warm weather.

The earliest that you can plant catharanthus in Savoy is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant catharanthus and expect a good harvest is probably August. Any later than that and your catharanthus may not have a chance to fully mature. If you are starting your catharanthus indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Savoy. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Savoy is just an average the actual date of last frost is different every year. Half of the time in Savoy it frosts late in the year after April 15 so be sure to be ready to cover your catharanthus in the event of a late frost.

USDA Zone Info for Savoy

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Savoy

You may be interested in your other planting guides for Savoy.